List of sources:
Cape of Good Hope. Report of the Executive Committee of the King William's Town Public Museum, 1897.
FamilySearch: James Leighton. https://ancestors.familysearch.org/en/G4HJ-PY4/james-leighton-1855-1930 AND https://www.familysearch.org/ark:/61903/3:1:33SQ-G5FW-NMJ?view=index&personArk=/ark:/61903/1:1:7J5R-912M&action=view&cc=1779109&lang=en
Gunn, M. & Codd, L.E. Botanical exploration of southern Africa. Cape Town: Balkema, 1981.
Jenkins, E.F. & Grindlay, J.E. (Compilers). King William's Town directory, visitors' guide, and residents' handbook (p. 34, Naturalists' Society). King William's Town: Frontier Publishing Syndicate, [1897].
Kaffrarian Watchman, 5 November 1886, p. 3, King William's Town Naturalists Society.
King William's Town Botanic Gardens. Report, 1882-1888.
King William's Town Naturalists' Society. Minute Book, 1884-1899. (Kaffrarian Museum, King William's Town).
Malherbe, D.F. du T. Family register of the South African nation, 3d ed. Stellenbosch: Tegniek, 1966.
South African Association for the Advancement of Science. Report, 1910, 1917, 1918.